Tool Wear Mechanisms When Machining Nicked Alloyed Cast Irons

The working environment, performance requirements, chemical composition and metallographical structure were analysed firstly. The technical requirements on roller casting was also clearified. Thermal shock resistance of Al₂O₃ /TiC gradient ceramic was simulated by FEM. The tool life and wear mechanisms was inrestigated when the new tool machining cast irons with no, low and high Ni centent.Transient temperature field and thermal stress field under laser shock of Al₂O₃ /TiC gradient ceramic were simulted by ANSYS. The results show that thermal shock resistance of Al₂O₃/TiC gradient ceramic is superior to the homogeneous ceramic.By machining cast irons with no, low and high Ni centent, the results show that Al₂O₃/TiC gradient ceramic tool is superior to cemented carbide tool YS10 under the same condition. At the cutting speed of 150m/min, the mainly fracture mode is flank wear when machining cast irons with low Ni content, the main fracture mode becomes rake face wear when machining cast Irons with high Ni content. At the low cutting speed (75m/min), the main fracture mode is flank wear; at the high cutting speed (250 m/min), the main breakage mode is rake face spalling and tool nose chipping.